IUDs use has no impact on the ability to conceive: AJOG study

Authors Jeffrey F. Peipert et al searched the medical literature for a longitudinal study that evaluates contemporary IUD use and fertility in patients in the United States comparing current Food and Drug Administration (FDA)-approved devices and other contraceptive methods. The goal of their prospective cohort study was to evaluate the association of IUD use and time to conception in a cohort of women who discontinued their contraceptive method to attempt conception. Authors hypothesized that IUD use would be associated with longer time to conception after stopping a contraceptive method. In addition, they were interested in the association of past STI, specifically Mycoplasma genitalium and C trachomatis, with time to conception.

The Fertility After Contraceptive Termination Study is a multicenter, prospective cohort study of women stopping their contraceptive method to attempt conception. Researchers recruited participants between 2011 and 2017. Participants were a convenience sample of women recruited from academic centers in Philadelphia, PA; Los Angeles, CA; St. Louis, MO; Indianapolis, IN; Aurora, CO; and Salt Lake City, UT. Women were eligible if they stopped their contraceptive method within the past 120 days before enrollment, were between 18 and 35 years of age, had no history of infertility or sterilization, and had at least 6 months of follow-up. Baseline data included demographic and reproductive characteristics, past contraceptive use, nucleic acid amplification testing for sexually transmitted infections, and serology for past infection with Chlamydia trachomatis, Trichomonas vaginalis, and Mycoplasma genitalium. The primary exposure was intrauterine device use (ever); the primary outcome was time to conception. All participants were observed longitudinally for up to 24 months.

• Of the 461 participants, mean age was 28.2 years, 178 (38.7%) were Black, 157 (34.1%) were considered as low socioeconomic status, and 275 (59.7%) had a history of intrauterine device use.

• Without adjusting for any covariates, the median time to conception was shorter for participants who had a history of intrauterine device use (5.1 months) than participants who never used an intrauterine device (7.5 months).

• After controlling for potential confounders, the association of past intrauterine device use with time to conception was not statistically significant (adjusted hazard ratio, 1.25).

• In this multivariable model, age, nulligravidity, Black race, low socioeconomic status, and past Mycoplasma genitalium infection were associated with longer times to conception (hazard ratio, 0.76).

• Conception by 12 months was lower in participants with past Mycoplasma genitalium infection (68% vs 80% without past infection; P=0.19).

Researchers found no association of a history of IUD use (ever) with time to conception. In fact, the effect estimate was in the positive direction: time to conception was shorter for participants with a history of IUD use than participants without such history. However, this association was not statistically significant. Median time to conception and rates of infertility (failure to conceive within 1 year) were higher than that reported in the literature, but this difference may be because of the characteristics of the patients enrolled in study (eg, greater percentage of women of low SES, greater percentage of women of color, and high rates of past STI). Other typical factors associated with lower conception rates (eg, age, nulliparity, marital or cohabitation status, and Black race) were associated with longer times to conception, as expected. Serologic evidence of past M genitalium infection was also associated with infertility; this is an intriguing finding. Past infections with C trachomatis or T vaginalis were not associated with time to conception.

The strength of this study was the multicenter recruitment of a diverse sample, prospective recruitment and follow-up, and a high number of IUD users. Authors tested for current STIs and obtained serologic data regarding past STIs to ensure control for past STIs in our multivariable model.

The study does have some limitations. First, although sample size was large, this was a convenience sample. Even with a large sample size, the number of positive current infections was too small for meaningful analysis. In addition, it is possible that some participants may have not accurately recalled the precise date they stopped their method and started to attempt conception. This may also have varied between methods. Furthermore, they could not assess the duration of IUD use in this cohort.

The authors concluded, "We found no evidence to support the association of IUD and time to conception or infertility. Patients and providers should be reassured that contemporary IUDs have no impact on the ability to conceive. Further studies should assess the role of specific STI pathogen (ie, M genitalium) and race on time to conception and whether screening and treatment for M genitalium can reduce the risk of infertility."

Source: Jeffrey F. Peipert, MD, PhD; Qiuhong Zhao, MS; Courtney A. Schreiber; American Journal of Obstetrics & Gynecology AUGUST 2021